The biggest question, though, is about their head coach: Just how good is Eric Mangini?

We’re nearly three seasons into the Mangini Era, and the answer is still hard to find. Mangini is 22-22 as the Jets’ coach, not including his one playoff loss.

He is the definition of mediocrity – exactly .500.

The first-year success that earned him the handle “Mangenius” and a trip to the playoffs was canceled by last year’s 4-12 disaster. This season, Mangini has mixed big victories with perplexing losses to craft a resume that would not have suitors lining up at his door.

Next month will mark three years from when Woody Johnson plucked Mangini from Bill Belichick’s staff. The most memorable moments of Mangini’s time in New York have been his dinner with Tony Soprano and a couple of dead-fish handshakes with Belichick.

But Mangini has a chance in these final four weeks of the regular season and into the playoffs to show what he’s capable of. He followed up one of his best coaching jobs in Tennessee with one of his worst against Denver. The Jets came out listless and played sloppy football in the 34-17 loss, prompting Mangini to admit he needs to do a better job.

The Jets now face four opponents with a combined record of 19-29. An AFC East title is a must. There is no excuse if they somehow surrender this one-game lead to a Patriots team without its franchise quarterback or a Dolphins team a year removed from 1-15.

Mangini has one year left on his four-year contract, and, barring a complete collapse, already has earned himself an extension. But this isn’t about contracts. This is about his future with the Jets. Is he the right guy to end 40 years of Mud Bowls, mistakes and mediocre football that made the Same Old Jets?

Three years ago, the Jets thought it was a sure bet to pluck their new coach off the Belichick coaching tree, but we have seen that tree had some weak limbs. If Belichick assistants were stocks, Romeo Crennel and Charlie Weis would be GM and AIG. To be fair, Mangini has done better than his fellow Belichick disciples, but he still seems to be learning on the job. The 37-year-old looks great one minute, then outsmarts himself like Sunday, when he called for a pass on fourth-and-1.

Mangini came to the Jets as a defensive guru, but his defenses have been inconsistent at best. Last year, the team was awful against the run. This year, their pass defense is hideous. The Jets don’t have a shutout under Mangini. By contrast, Herm Edwards had three in his first three seasons with the Jets.

The pressure landed squarely on Mangini’s shoulders to deliver this season the minute Favre stepped off that plane in Cleveland. Johnson and GM Mike Tannenbaum made it clear they were going for it this year.

As the Jets prepare for the 49ers this week, they are on track to accomplish many of their goals. The remaining schedule contains more cupcakes than Kris Jenkins’ cupboard, so the playoffs should be a lock. Mangini needs to deliver the Jets’ first division title since 2002 and his first playoff victory.